Molecular biology of coronaviruses: current knowledge

Abstract

The unpredictable emergence of new infectious diseases can be seen as a threat to human health and global stability, despite extraordinary progress in development of countermeasures such as diagnostics, vaccines, and treatments. Diseases caused by coronaviruses are a few of many examples of emerging infectious diseases in the modern world (Morens and Fauci, 2013). Coronaviruses (CoVs) are emerging and re-emerging pathogens and several of them have caused serious problems in humans and animals (Lau and Chan, 2015). These include varying symptoms ranging from mild respiratory illness to severe infections causing death. Apart from the respiratory tract, coronaviruses can also affect other organs in the body, such as the gastrointestinal tract, liver, kidney, and brain of both humans and animals. The pandemic of severe acute respiratory syndrome (SARS) in 2002–2003, the emergence of Middle East respiratory syndrome (MERS) in 2012 and the emergence of a new coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of the coronavirus disease 2019 (COVID-19) pandemic, are all examples of human infections leading to significant fatality caused by coronaviruses (Anindita et al., 2015; Guarner, 2020; WHO, 2020).